In gear trains, backlash refers to the clearance between gears in the gear trains, specifically the clearance between the teeth of meshed gears. For many gear train designs, a certain amount of backlash is desirable and greater or lesser amounts of backlash may be less desirable. Gear trains may be designed with systems or methods to adjust the amount of backlash, either at the time the gear train is assembled or during later adjustment of the gear train.